RU31821U1 - FACE SEAL OF ROTATING SHAFT - Google Patents

Description

Mechanical seal of a rotating shaft A useful model relates to mechanical engineering, namely to mechanical seal of a shaft with integrated refrigerators, which are used to seal the rotating shafts of units in various sectors of the economy.

Cooled mechanical seals consist of a sealing assembly with a limited operating temperature and a system that ensures that the temperature in the seal zone is lowered to an acceptable temperature.

The known design of the mechanical seal for oil pumps with a closed-circuit cooling system comprising a sealing assembly and an integrated

a refrigerator including two bushes coaxially located relative to the shaft with a sealed intershell end, forming the refrigerator case, and an internal cylindrical partition, screw grooves are made on the inner surface of the refrigerator case on the shaft side, increasing heat transfer (A. I. Golubev, reference book. Seals and sealing technology.Machinery, M., 1986, S. 444, Fig. 13.18, see the appendix).

2003110779

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IPC: F04D 29/10, F16J 15/44

The closest technical solution to the proposed technical solution is the design of a double mechanical seal with a rotary shaft type DNT, manufactured

Nalchik engineering plant, with a heat exchange device (refrigerator) open type in the stuffing box. This design of the refrigerator is compact and simple, where the coolant flows into the cooling cavity under pressure through openings in the housing of the unit. But the use of a refrigerator open on the outside diameter reduces the reliability of the mechanical seal, since in this design the refrigerator is sealed relative to the pump casing (unit) by rubber rings, which, as a result of the operation of the pump (especially at elevated temperatures)

quickly lose their elasticity (carbonized) and do not ensure the tightness of the junction of the refrigerator and the unit body. Tightening the refrigerator interior gasket

simultaneously with the outer gasket is difficult and unreliable due to thermal deformations and inaccuracies in the manufacture of parts together with the high rigidity of the flat gaskets. In addition, the leakage of the inner gasket cannot be controlled.

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The technical task of the proposed solution is to increase the reliability of the mechanical seal of the shaft with a refrigerator open in outer diameter by increasing its tightness.

The essence of the proposed technical solution lies in the fact that in the mechanical shaft seal, the contents are sealed;

the contact formed by the elements of the grill; ayup; of the fixed and fixed units and included in the closed circuit; cool the liquid; the refrigerator is closed by the open housing diameter of the unit body and sealed with a flat ring gasket relative to the unit case (at the joints) to ensure the tightness of the refrigerator cavity, ring gasket made of thermally expanded graphite,

preloaded additionally introduced by a wave spring.

A compression ring is inserted between the graphite ring gasket and the wave spring.

The wave spring is split.

In FIG. 1 shows a general view of a mechanical seal with a refrigerator (longitudinal section); in FIG. 2 - remote element A of FIG. 1.

A shaft 2 passes through the housing 1, on which the sealing contact 3 of the mechanical seal and the refrigerator 4 are placed, which is included in a closed coolant circuit (Fig. 1).

When installing the cavity of the refrigerator 4 are closed by the housing 1 of the unit, forming a closed loop of cooling water circulation. To ensure the tightness of the cavity of the refrigerator, its junction with the body of the unit is sealed (Fig. 2). For this, a gasket 5 is made on the refrigerator (its end part), made of thermally expanded graphite of the “graphlex” type (which withstands high temperature and has good deformation), a steel compression ring 6 and the refrigerator are installed in the stuffing box of the unit, in the end of which

pre-installed wave spring 7, which abuts against the ring 6 compresses the gasket 5.

The implementation of the split wave spring (in the form of half rings) makes it more convenient to place it at the end of the stuffing box of the unit body.

Mechanical seal operates as follows.

Under the action of a pressure differential created by an external source, water (cooling medium) enters the cavity of the refrigerator 4, circulating in a closed circuit.

The proposed design allows to increase the sealing of the junction of the refrigerator with the body of the unit due to the use of heat-resistant, deformable gaskets made of expanded graphite, which is pressed by a wave spring, which makes it possible to compensate for the inevitable variation in the sizes of stuffing box chambers of different units, improving the working conditions of the mechanical seal and increasing its reliability.

The utility model can be especially effectively used in the development and modernization of mechanical seals for pumps pumping high-temperature media, for example

hot petroleum products.

Claims (3)

1. A mechanical seal of a rotating shaft, comprising a sealing contact formed by elements of a rotating and fixed units, and a refrigerator included in a closed circuit of the coolant circulation, closed by an assembly outer casing and sealed with a gasket relative to the assembly casing, characterized in that the gasket is made of thermally expanded graphite, preloaded by an additionally introduced wave spring. 2. The seal according to claim 1, characterized in that between the graphite gasket and the wave spring, a compression ring is introduced. 3. The seal according to claims 1 and 2, characterized in that the wave spring is split.